Oh my god, this is so fucking sad???? I found this manga because I read the author's more recent age-gap love story, and holy shit, no wonder they're writing fluffy wholesome no-stakes romances now. I feel like I need to watch an hour of videos about puppies and babies laughing just to decompress from the sheer amount of tragedy stuffed into this plot. The last chapter ends on a more hopeful note but... jeezus, I was not prepared at all coming into this based on their other works. Be warned all ye who wish to read. Many feels lie ahead.
In order to attain immortality, the Grim Reaper began devouring the souls of people. To gather more souls, he created the Larvae and unleashed them upon the world.
Cyan is a former member of the Argent Cavaliers, an order of holy knights dedicated to eradicating Larvae and founded by the Grim Reaper's sister, Lemuria. Cyan left the Argent Cavaliers in order to hunt down the Grim Reaper with Jade, a descendant of Lemuria, and put an end to the Larvae threat once and for all.